The proposed study will examine the catecholamine, cardiovascular, and sel-report responses to an effortful active shock avoidance condition and to a passive shock experience condition in normotensives and hypertensives. The plasma chatecholamines will be measured by high performance liquid chromatography with electrochemical detection in order to separate epinephrine and norepinephrine. The cardiovascular measures will include heart rate, blood pressure and finger pulse amplitude. The self-report questionnaires will assess feelings of anxiety and anger after each test condition and will also assess personality traits including anxiety, anger, repression, assertiveness, and anger arousal. The effortful active shock avoidance condition is designed to elicit active coping responses and is hypothesized to cause increases of plasma norepinephrine, increases in systolic blood pressure and heart rate, and increases in self-reported anger. The passive shock experience condition is designed to elicit passive coping responses and is hypothesized to cause increases in plasma epinephrine and self-reported anxiety. These responses will be measured in normotensive and hypertensive male adults. Both effortful active shock avoidance and passive shock experience conditions will be presented to the subjects individually in Study One. In Study Two, the subjects will work as interdependent dyads and as competing dyads during the two conditions. The results will provide a better understanding of the mechanisms of catecholamine release which may be a component of the etiology of coronary heart disease and hypertension.